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+# Phase 2: Online Board Feature
+
+> **For agentic workers:** REQUIRED SUB-SKILL: Use superpowers:subagent-driven-development (recommended) or superpowers:executing-plans to implement this plan task-by-task. Steps use checkbox (`- [ ]`) syntax for tracking.
+
+**Goal:** Implement the Online Board feature -- the main flight status display with search by flight number, route, departure, or arrival. Includes start page, search results, and flight details.
+
+**Architecture:** Feature-isolated module at `src/features/online-board/` with hooks, components, and services. Uses TanStack Query hooks from shared layer. URL-driven state with route validation.
+
+**Tech Stack:** React 19, TanStack Query v5, Zustand, PrimeReact (Accordion, AutoComplete, Calendar), react-i18next, CSS Modules
+
+**Depends on:** Phase 1 Foundation (complete)
+
+---
+
+### Task 1: Online Board Feature Hooks
+
+**Files:**
+- Create: `react-app/src/features/online-board/hooks/useOnlineBoardApi.ts`
+- Create: `react-app/src/features/online-board/hooks/useFlightNavigation.ts`
+- Create: `react-app/src/features/online-board/hooks/index.ts`
+
+Feature-specific hooks wrapping shared query hooks with online-board-specific logic.
+
+- [ ] **Step 1: Create API hook**
+
+`useOnlineBoardApi.ts` wraps the shared query hooks with board-specific params and adds the `getFlightDaysByNumber` and `getFlightDaysByRoute` calls for calendar disabled dates.
+
+- [ ] **Step 2: Create navigation hook**
+
+`useFlightNavigation.ts` provides `navigateToSearch`, `navigateToDetails`, `navigateToStart` using React Router's `useNavigate` with URL builders from shared utils.
+
+- [ ] **Step 3: Commit**
+
+---
+
+### Task 2: Search Filter Components
+
+**Files:**
+- Create: `react-app/src/features/online-board/components/filter/FlightNumberFilter.tsx`
+- Create: `react-app/src/features/online-board/components/filter/FlightNumberFilter.module.css`
+- Create: `react-app/src/features/online-board/components/filter/RouteFilter.tsx`
+- Create: `react-app/src/features/online-board/components/filter/RouteFilter.module.css`
+- Create: `react-app/src/features/online-board/components/filter/OnlineBoardFilter.tsx`
+- Create: `react-app/src/features/online-board/components/filter/OnlineBoardFilter.module.css`
+
+PrimeReact Accordion with 2 tabs: Flight Number search and Route search.
+
+- [ ] **Step 1: Create FlightNumberFilter**
+
+Input fields: flight number (SU prefix + 4 digits + optional suffix letter), date picker. Validates input, calls API for disabled dates.
+
+- [ ] **Step 2: Create RouteFilter**
+
+Input fields: departure autocomplete, arrival autocomplete, swap button, date picker, time range. Validates stations, calls API for disabled dates.
+
+- [ ] **Step 3: Create OnlineBoardFilter (accordion wrapper)**
+
+PrimeReact Accordion with 2 panels. Manages active tab state.
+
+- [ ] **Step 4: Commit**
+
+---
+
+### Task 3: Flight Display Components
+
+**Files:**
+- Create: `react-app/src/features/online-board/components/board/FlightCard.tsx`
+- Create: `react-app/src/features/online-board/components/board/FlightCard.module.css`
+- Create: `react-app/src/features/online-board/components/board/FlightList.tsx`
+- Create: `react-app/src/features/online-board/components/board/FlightList.module.css`
+- Create: `react-app/src/features/online-board/components/board/FlightStatusBadge.tsx`
+
+Components to display flight search results.
+
+- [ ] **Step 1: Create FlightStatusBadge**
+
+Renders colored badge based on FlightStatus enum (green=arrived, orange=delayed, red=cancelled, etc.)
+
+- [ ] **Step 2: Create FlightCard**
+
+Expandable card showing: departure/arrival times, cities, airline, status. Click to expand shows leg details. Uses PrimeReact Card.
+
+- [ ] **Step 3: Create FlightList**
+
+Renders list of FlightCards. Highlights closest flight to search time. Manages expanded state.
+
+- [ ] **Step 4: Commit**
+
+---
+
+### Task 4: Flight Details Components
+
+**Files:**
+- Create: `react-app/src/features/online-board/components/details/FlightDetails.tsx`
+- Create: `react-app/src/features/online-board/components/details/FlightDetails.module.css`
+- Create: `react-app/src/features/online-board/components/details/FlightLegDetails.tsx`
+- Create: `react-app/src/features/online-board/components/details/FlightLegDetails.module.css`
+- Create: `react-app/src/features/online-board/components/details/FlightMiniList.tsx`
+- Create: `react-app/src/features/online-board/components/details/FlightMiniList.module.css`
+
+Components for the flight details page.
+
+- [ ] **Step 1: Create FlightLegDetails**
+
+Per-leg detail panel: departure/arrival info, times (scheduled/estimated/actual), gate, terminal, boarding status, transfer info.
+
+- [ ] **Step 2: Create FlightMiniList**
+
+Left sidebar list of all matching flights. Highlights selected. Click emits selection change.
+
+- [ ] **Step 3: Create FlightDetails**
+
+Main details view. For direct flights: single FlightLegDetails. For multi-leg: timeline with FlightLegDetails per leg + transfer segments.
+
+- [ ] **Step 4: Commit**
+
+---
+
+### Task 5: Start Page
+
+**Files:**
+- Create: `react-app/src/features/online-board/components/StartPage.tsx`
+- Create: `react-app/src/features/online-board/components/StartPage.module.css`
+- Modify: `react-app/src/features/online-board/components/OnlineBoard.tsx`
+
+- [ ] **Step 1: Create StartPage**
+
+Renders: page title, OnlineBoardFilter (search form), hero section with 4 info tiles, PopularRequests widget. Uses MetaTags for SEO.
+
+- [ ] **Step 2: Update OnlineBoard entry component**
+
+Replace placeholder with router that renders StartPage on `/onlineboard` and other pages on sub-routes.
+
+- [ ] **Step 3: Commit**
+
+---
+
+### Task 6: Search Results Page
+
+**Files:**
+- Create: `react-app/src/features/online-board/components/SearchPage.tsx`
+- Create: `react-app/src/features/online-board/components/SearchPage.module.css`
+- Create: `react-app/src/ui/date-tabs/DateTabs.tsx`
+- Create: `react-app/src/ui/date-tabs/DateTabs.module.css`
+- Create: `react-app/src/ui/time-selector/TimeSelector.tsx`
+- Create: `react-app/src/ui/time-selector/TimeSelector.module.css`
+
+Shared search results page for all 4 search types (flight number, route, departure, arrival).
+
+- [ ] **Step 1: Create DateTabs component**
+
+Horizontal date navigation (today, tomorrow, +2, etc.) with disabled dates. Sticky at top.
+
+- [ ] **Step 2: Create TimeSelector component**
+
+Time range picker (from/to sliders or inputs).
+
+- [ ] **Step 3: Create SearchPage**
+
+Receives search type and params. Renders: DateTabs, TimeSelector, FlightList, loading/empty states. Calls useFlightsQuery with params. Handles date/time changes via URL navigation.
+
+- [ ] **Step 4: Commit**
+
+---
+
+### Task 7: Flight Details Page
+
+**Files:**
+- Create: `react-app/src/features/online-board/components/DetailsPage.tsx`
+- Create: `react-app/src/features/online-board/components/DetailsPage.module.css`
+
+- [ ] **Step 1: Create DetailsPage**
+
+Renders: DateTabs, FlightMiniList (sidebar), FlightDetails (main). Fetches flight details via useFlightDetailsQuery. Handles flight selection from mini-list. Uses MetaTags + FlightJsonLd for SEO.
+
+- [ ] **Step 2: Commit**
+
+---
+
+### Task 8: Route Definitions with Validation
+
+**Files:**
+- Create: `react-app/src/features/online-board/components/ValidatedRoute.tsx`
+- Modify: `react-app/src/routes/onlineboard/page.tsx`
+- Create: `react-app/src/routes/onlineboard/flight.[params].tsx`
+- Create: `react-app/src/routes/onlineboard/departure.[params].tsx`
+- Create: `react-app/src/routes/onlineboard/arrival.[params].tsx`
+- Create: `react-app/src/routes/onlineboard/route.[params].tsx`
+- Create: `react-app/src/routes/onlineboard/[params].tsx`
+
+- [ ] **Step 1: Create ValidatedRoute wrapper**
+
+Generic wrapper that validates URL params, redirects to 404 on invalid.
+
+- [ ] **Step 2: Create route pages**
+
+Each route page: parses params, validates, renders SearchPage or DetailsPage with appropriate type.
+
+- [ ] **Step 3: Verify all routes work**
+
+Test: `/onlineboard`, `/onlineboard/flight/1234-2026-04-03`, `/onlineboard/route/SVO-LED-2026-04-03-08002200`, `/onlineboard/SU1234-2026-04-03`
+
+- [ ] **Step 4: Commit**
+
+---
+
+### Task 9: Build Verification
+
+- [ ] **Step 1: Run production build**
+
+Verify build succeeds with all new components.
+
+- [ ] **Step 2: Final commit**
+
+---
+
+## What This Plan Produces
+
+After completing all 9 tasks:
+- Complete Online Board feature with start page, 4 search result types, and flight details
+- Reusable UI components (DateTabs, TimeSelector)
+- Flight display components (FlightCard, FlightList, FlightDetails)
+- Search filter form with flight number and route tabs
+- URL-driven routing with param validation
+- SEO (MetaTags + JSON-LD) on all pages